Field of the Disclosure
The disclosure relates to a sensing technique of a charge sensor, and particularly relates to an image sensing device, a system and a method thereof and a charge sensing device.
Description of Related Art
In view of today's various sensors, physical or chemical variations occurred therein are converted into a charge quantity, so as to convert the variations into a sensing signal. Such type of sensors is, for example, a phototransducer, a piezoelectric sensor or a biochemical reaction sensor. The phototransducer is sensitive to visible lights and other types of electromagnetic rays (for example, a gamma ray, an X-ray, an ultraviolet light, an infrared light, etc.) to correspondingly generate induced charges. Based on the induced charges generated by the phototransducer, an intensity variation of the electromagnetic ray is detected. Since a high-energy electromagnetic ray (for example, the gamma ray or the X-ray) can penetrate objects (for example, a human body), appearances or distribution of articles (for example, organs) in the object can be learned without spoiling the object. Therefore, a flat panel detector used for sensing the high-energy electromagnetic ray can be applied in many fields, particularly in radiation medicine, animal experiments, industrial non-destructive testing, etc., for image capturing.
In the field of medicine, it's not to expect that human body is irradiated with high-energy electromagnetic ray. Besides, the required intensity of high-energy ray, X-ray for example, is different under different fields and situations of image inspection scenarios. For example, body thickness or imaging position of a testee can be different such that the required intensity of X-ray should be adjusted accordingly. Therefore, the amount of induced charges sensed by the phototransducer in the flat panel detector can vary significantly and the post-end image readout circuit needs to perform proper adjustment to amplify the induced charge signal accordingly. As a result, an operator is required to properly process the image data obtained from the flat panel detector according to personal experiences to facilitate subsequent medical diagnosis or video output. Presently, flat panel detectors process the image data in the digital format with high resolution to obtain useful information. Consequently, the image readout circuits usually include high resolution data converters, which is very costly. Moreover, the flat panel detector is required to perform lots of processing, which hinder real-time image sensing.